Nearly 10 percent of women who took our Oprah.com health poll said they use a tampon for more than 10 hours.

"No more than 6 to 8 hours, you should not wear a tampon for longer than that," Dr. Masterson warns. "Women are very busy so they'll try to push the limits." However, Dr. Masterson says that a tampon inside can be a medium for bacteria and using one for longer than recommended can lead to uterine infections and toxic shock syndrome.

Could a tampon get lost?

"It cannot get lost, but it can get stuck," Dr. Masterson explains. "Your vagina is a blind pouch. It can get wedged behind the cervix." If a tampon does become stuck, it absolutely needs to be removed."

Think this isn't a common occurrence? "I see this at least once a month," Dr. Masterson says.